A rough material like burlap that is used to make sacks or bags.
Sackcloth can make people think of old-fashioned things or hard times.
Examples:
The sackcloth is scratchy.
She made a bag out of sackcloth.
The sackcloth is brown and rough.
I made a shirt out of sackcloth, but it was too itchy!
In the old days, people wore sackcloth clothes all the time.
The sackcloth bag was heavy and rough.